The Animal Core is designed to achieve efficiencies of cost and most effective utilization of the expertise of individuals involved in design and implementation of studies involving animals. The Animal core will provide the most cost-efficient mechanism for procurement and utilization of research animals. Planning and execution of experiments involving experimental animals will be implemented in conjunction with the Animal core. A mechanism will be provided for interproject and intercore collaboration at all stages of study design and analysis. Efficient use of research animals will be insured by a thorough coordination of experiments among biostatistics, animal core and project investigator personnel. Long-range goals will be set for policies of animal handling, model development and experimental design. The Animal core Principal Investigator has several years of experience in running a similar animal core. Careful attention to cost analysis supports the rationale for establishing a separate Animal Core.